Prestashop Multistore Domain Name issue

Only Professional Developers with Experience in Prestashop coding need apply please.

We have a multistore prestashop shop on [url removed, login to view] . One multistore shop is [url removed, login to view] we have forwarded URL [url removed, login to view] to [url removed, login to view] . Same with [url removed, login to view] : [url removed, login to view]

When we click "add to cart", we get blank screen, see attached image. We also cannot log in. Only happens on some browsers, not all browsers.

It doesnt matter how this works, so long as the address bar has "[url removed, login to view]". Is there a way to mimic [url removed, login to view] to [url removed, login to view] . so if we click [url removed, login to view] it goes to [url removed, login to view] Thank you. Could be a cookie / session issue...

We are web enthusiast from the India with more than 8 years of experience on creating a websites, Customer Relationship Management Softwares(CRM using Vtiger, Sugar CRM), Mobile Application Development, Graphic DesigniMás